350HP for the GT-HO is at the flywheel it says.

The Bathurst one was with the 186 heads.

The HG is the last 350's.

I believe the Holdens were maybe RW-HP But it does not say, they were pricks like that.

They are figures out of books I have for years and wrote down notes.

Ford have power figures of 1972 351 2V of 161HP at 4000 and a Cobbra Jet 351 is 245HP at 5400 net, both run 8.6:1
Now the 1971 351 2V is 240HP at 4600 and the 351 4V is 285HP 5400 Gross.

M38192 is not a cam number at all but for a catalogue I believe.

One has to wonder why Holden made a 9.7:1 5.0L and the 253 stays the same as.
I think it had to do with how the cam performs it's role she losses volume efficiency because of the exhaust being longer most, likely I would think and all things being equal in that, is why it maybe so.

If old mate from MM says that the HZ now out performs the HJ, I find that hard to believe and 11.1 sec to 100KM/H piff ! that's gutless as in my books.
I just had a look at the book and it's an automatic in a picture of the HZ GTS 5.0L but the buggers don't say so.

Edited by user Monday, 15 February 2016 8:43:31 PM(UTC)  | Reason: Oops, stuffed up the "quote"again!

L34 used flat top pistons but combustion chamber cc was gained when machined for bigger valves. HJ piston has smaller sump than HT-HQ.

LH gets the HQ engine at release and it changes to the HJ engine at engine number HT24413. HJ engine uses the F5000 style block which was first used in a GMH product in L34.

Edited by user Monday, 15 February 2016 8:32:36 PM(UTC)  | Reason: Not specified

L34 Repco stronger piston than the normal piston I believe with a flat top and the L34 valves in the head = more cc in that chamber.

The L34 block I seen one with HZ prefix in a Torana I looked to buy back in 1982 but it was just too shabby a car it looked as all the body work had a hard life it had a holley but no twin coil dizzy and std rocker buckets on it.
There is the L34 block that they used for racing with the HP cast on the block, I have never seen one but a dude has invited me to come see the one he has, it's not a early HT block like I had.

I thought the different block changed the ribbing at the back in the late HQ and with it when looking in the valley where the cam sits looking at it the early ones casting dips down and the newer one is a flat like casting. I could be wrong it may of been the HJ.

I also doubt they'd have got a 253 mixed up with a 308. I've owned as used cars HQ Deville, HJ Deville, 2 x 308 HJ Premier and a 308 4spd HZ Kingswood sedan. Obviously the 2 x Devilles and 2 x HJ Prems were autos. The 2 x Devilles had twin exhaust, the 2 x Prems single. The HZ had a dual exhaust. All of the auto cars were 2.78 except the HJ Deville which was a 3.08. The HZ was 3.36. All cars were dead stock, original drivetrain, all like 100,000kM or less. The quickest was obviously the HZ, so it may well be what you say ie the HJ was an auto.

The 400 was going to be the engine for the HV (HQ replacement), and it is in HJ documents up until late 1973, this is why the HQ Old Man Emu (later the 350Z), the Max Wilson Gold HQ GTS350 and a few others had 400ci engines in them. Supposedly there was a 400 Olds engine in a HQ as well, I think this is the 6.6L engine as used in Transams as in Trigger from Smokey and the Bandit. They were expensive as you say, and they were only a 2BBL engine in GM passenger cars. I'm near certain if you put a bog standard 1972-4 2BBL 400ci Chev in a HJ with a TH400 and 2.78 rear axle, that it'd be slower than a HJ 308 with the same driveline and probably use a lot more fuel. Plus a full cast iron 350 weighs about 70 odd kg more than a 308.

Had a bloke with a Ramsay Marine 308 and it had HP cast on the block and one dude has 13 308 blocks with one that is with a HP and it's not a HT engine prefix but he wants me to go see it.
I have has one dude say he has seen one with HP on both sides but bigger than the normal HP casting size.
I have seen a HP block with a small X above it on the net.

Yes I have the same article. Do you remember what Street Machine it is in - I only have the copy handy and it doesn't tell me what edition. I want to look closely and see if it is a HX manifold or a HZ one and also check the early one to see if it is HT-HQ or HJ.

Interesting that in the same test the Edelbrock Performer flowed to a theoretical 327hp, and the Torker 342hp, all with stock heads so there is not much to be gained by swapping out an early manifold for a Performer. Shows why the L34 and GroupC cars managed so much hp with the early manifold.

They also state they were very generous to the pollution manifold. All of the manifolds except the pollution one were capable of flowing more with modified heads but the pollution one was already restricting air flow to the stock heads. It flowed 75.6cfm@10" H20 and 119.5cfm@25" H20.
The standard pre pollution manifold only started to become a restriction at flow past 115cfm@10" H20 or 182cfm@25" H20 which is really good as the stock heads were only good for respectively 96.6cfm and 152.7cfm.

Edited by user Tuesday, 16 February 2016 2:44:50 PM(UTC)  | Reason: Not specified

I just talked to a friend about these figures who has them as well. The ones from Ian Tate are GMH dyno figures and are SAE net figures using GMH's engine dyne setup for SAE measurements.

The 350hp for the GT-HO will be a gross figure.

If you read the October 1971 Wheels magazine, Mel Nichols talks about a car Ford called a PhaseIII+. It was fitted with all the good Ford USA Shelby bits, and would rev to 7000rpm. It made 232hp at the rear wheels which would be about 350hp gross engine hp so it may be the same engine Mick Webb is talking about. Over the quarter in a PhaseIII you'd be looking at high 13's and probably crack 100mph with that engine.

As a comparison the untouched but properly tuned HG GTS350 AMC tested put down 207hp at the rear wheels, it was about 14.7s @ 95mph 1/4 mile. This will be the engine that GMH got 224hp SAE net out of. The 214hp version is the 300hp HT engine, so doing rough maths the 224hp SAE net you'd probably expect 315hp gross for the HG engine.

Also found the road test on the new LX SS 5.0L. This is an important test as it is the first time the 308 got a proper 2" dual exhaust, and this is the HJ engine (not the later LX with the HX engine). Wheels July 1976. 0-150km/h (not sure why 150) 16.8s, 0-400m 15.6s. managed 97mph in 3rd at 5500rpm but it'd only rev to 4800rpm in top gear (needs a less restrictive air cleaner) so managed 117mph. With a decent air cleaner it'd probably exceed 130mph. This is a fairly light car at 1290kg, but it also has a 2.78:1 rear axle which equates to a HJ with a 3.08:1 rear axle. It'd be interesting to see how quick the car would be with an optional 3.08:1 rear axle which would give it similar gearing to a HJ GTS. The comments from the Journalist was something about this car being a rocketship and the first car they'd tested that made them look back to the "muscle car era" ie HT-HG GTS350 and GT-HO. I still can't find the HJ GTS road test with a dual exhaust, it was a 3.36 rear axle and also managed sub 16s quarters and not far off these Toranas. These had a step down exhaust (mufflers were smaller) though whereas the LX got a proper 2" twin.

The LX 5.0 SS had 13-inch wheels only from the factory.

The A9X could've had either a 2.60 or a 3.08 rear axle.

Dr Terry

Is Bill Tuckey's figures on the HT a "test" or is it re-hashing original road tests? Reason I ask is those figures look an awful lot like the figures published back when the cars were new, with the secondaries played with on the GTS350 plus the staffer in the car not letting them rev the engine past 5500rpm. The true potential of the car with published figures can only be found in AMC where they run it to peak power and acceleration test the car identically to how they were done in the late 60's and 70's. Mel Nichol's didn't get proper test results as he only had the car for a road test one week and was to do performance figures a week later. He got the car back a week later and it had been hobbled - he only recorded similar figures to what Bill Tuckey has quoted above. Robbo got a HG later and was blown away by the performance of the car. You can see the basics of what they said in Wheels in Joe Kenwright's article I put a link up to in post 80, right at the bottom of the text. I'll see if I can find the actual Wheels editions.

GMH definitely introduced new patterns for 308 and 253 and used them alongside the old patterns for a while. We have recorded blank (253) and HP (308) way after 253 and 308 castings appeared. They obviously just used the old patterns until they were unserviceable. The blank and HP also show you how far back they were working on the Holden V8. This usage of blank and HP is EH era, and they probably didn't change them even up until production as the engine sizes weren't finalised until late in the piece. Obviously the sides of the pattern didn't change much and there was no need to change the sides of the patterns until they needed new patterns for volume 308 production - remember 308 engines would only be a trickle of production after initial HT Brougham production until later in 1969. From memory 253 appears earlier than HP changes to 308.

Edited by user Wednesday, 17 February 2016 1:51:00 PM(UTC)  | Reason: Not specified

The car Castellan is referring to is KNK777, the ex Spencer Martin HDT car that caught fire at Sandown in 1969. It was fitted with 7 or 8" chromed steel wheels when that test was done, and being ex HDT would not be representative of a standard HT 81837.
The 350 engines for HDT were chosen by testing a container load on the GMH engine dyno. The best ones went to HDT. They were quite consistent, but the best of them were around 260hp.
The best times I ever saw, with a dead stock HT350, with 85,000 miles, 205/70 NCT tyres, super fuel, good grippy asphalt, shifting at around 5,200RPM and a timing spoon under the front wheel was a fairly consistent 14.94 at 147. And I have the event slips to prove it. Dr Terry would know more about 1/4 times than any of us, but my understanding is ET is mostly a measure of traction and technique, but trap speed is a better indication of actual horsepower.